AWS Wavelength

What it is

AWS Wavelength puts AWS compute and storage inside telecommunications providers' networks, at the edge of their 4G and 5G networks. Traffic from a mobile device to an application in a Wavelength Zone stays within the carrier's network, instead of travelling across the internet to an AWS RegionA separate geographic area where AWS runs its services, such as us-east-1 in Northern Virginia, made up of several Availability Zones. Most resources live in one Region; you choose Regions for latency, data residency, and the services you need.Glossary entry, which gives very low LatencyThe time between sending a request and receiving the response, usually measured in milliseconds. Distance and processing add to it; caching and serving users from nearby locations reduce it.Glossary entry to mobile and connected devices.

Use it for applications where every millisecond to the device matters, such as:

Game and media streaming, and augmented or virtual reality on mobile devices.
ML (Machine learning)Software that learns patterns from example data to make predictions or decisions, instead of following rules written by hand. A model is first trained on data, then used to make predictions on new data, which is called inference.Glossary entry inference at the edge, such as video analytics.
Connected vehicles, drones, and industrial IoT devices on a carrier network.

Concepts

A Wavelength Zone is a zone at a carrier location. It is a logical extension of its parent Region, managed by the Region's control plane. You opt in to a Wavelength Zone before you can use it.
Extend your VPC by creating a SubnetA range of IP addresses in a VPC, inside one Availability Zone. A subnet is public when its route table sends internet traffic to an internet gateway, and private when it does not.Glossary entry in the Wavelength Zone. Instances there talk to resources in the Region's AZ (Availability Zone)An isolated location within an AWS Region, made up of one or more data centers with their own power, cooling, and networking. The AZs in a Region are linked by fast, low-latency connections, so spreading resources across them protects against the failure of one site.Glossary entry over the VPC, so the edge part of an application can use databases and other services in the Region.
A carrier gateway connects Wavelength subnets to the carrier network: it allows inbound traffic from devices on the carrier network and outbound traffic to the carrier network and the internet. There is no inbound connection from the internet through it. It supports IPv4 and performs NAT (Network address translation)Rewriting the IP addresses in packets as they pass through a device, most often so that many private addresses can share one public address to reach the internet.Glossary entry, much as an internet gateway does in a Region.
A Carrier IP (Internet Protocol)The protocol that addresses and routes packets between networks. Each device has an IP address: IPv4 addresses look like 192.0.2.1, and IPv6 addresses are longer, like 2001:db8::1.Glossary entry address is the address that devices on the carrier network use to reach your instance, allocated from the Wavelength Zone's network border group.
Route traffic to the carrier gateway with a custom route table for the Wavelength subnet, for example 0.0.0.0/0 to the carrier gateway.

Services in a Wavelength Zone

You can run EC2 instances, EBS volumes, VPC subnets, and carrier gateways, and use EC2 Auto Scaling, Amazon ECS and Amazon EKS clusters, Systems Manager, CloudWatch, CloudTrail, and CloudFormation. An Application Load Balancer is available in some Wavelength Zones. Other services, such as databases, stay in the Region.

Security, resilience, performance, and cost

Security

Security groupA stateful virtual firewall for network interfaces, such as an EC2 instance's, whose rules can only allow traffic. Return traffic for allowed connections is allowed automatically, and a rule can refer to another security group instead of IP addresses.Glossary entry, Network ACLA stateless firewall for a subnet, with numbered allow and deny rules checked in order. Because it is stateless, return traffic needs its own rule, usually for a range of ephemeral ports.Glossary entry, IAM, and the rest of the VPC and EC2 security model apply as they do in a Region.
Because the carrier gateway accepts no inbound connections from the internet, instances in a Wavelength Zone are reachable only from the carrier network unless you route traffic another way.

Resilience

Each Wavelength Zone is a single location. For resilience, deploy to several Wavelength Zones, and keep the parts of the application that don't need edge latency, such as databases and API (Application programming interface)A defined way for one program to ask another for data or actions, such as a set of HTTPS requests and responses. Every AWS service is controlled through its API, which the console, the CLI, and the SDKs call for you.Glossary entry, in the Region's Availability Zones.
Design the application to fall back to the Region if a Wavelength Zone is unavailable.

Performance

Latency is lowest for devices on the same carrier's network near the Wavelength Zone. Traffic between a Wavelength Zone and the Region uses the VPC, with a smaller maximum packet size for private traffic (1,300 bytes).

Cost

EC2 instances in Wavelength Zones are paid for On-Demand or with Savings Plans; RI (Reserved Instance)A billing discount for committing to an instance type in a Region or Availability Zone for one or three years. It is not an instance: running instances that match are billed at the lower rate. AWS now recommends Savings Plans instead.Glossary entry are not available for Wavelength Zones.
Instance prices in Wavelength Zones differ from the parent Region, and data transfer in and out is charged at EC2 data transfer rates.

Monitoring

Use Amazon CloudWatch for instance metrics and AWS CloudTrail for API calls, managed from the parent Region.

Wavelength, Local Zones, or Outposts?

If the requirement is	Choose
Lowest latency to mobile devices on a 5G carrier network	AWS Wavelength
Low latency to users in a large city, for example for virtual workstations or live video	AWS Local Zones
AWS services in your own data center, for local systems or data residency	AWS Outposts
Cache and deliver content close to users worldwide	Amazon CloudFront

Reverse mindmap: when the question points here

Is it AWS Wavelength?

Yes, when the question says
- Lowest latency to mobile devices on 5G leads to AWS Wavelength
- Game streaming or AR on mobile networks leads to Instances in a Wavelength Zone
- Edge inference for connected vehicles on a carrier network leads to AWS Wavelength
Design it
- Extend the VPC to the carrier edge leads to Subnet in a Wavelength Zone
- Devices on the carrier network reach the app leads to Carrier gateway with a Carrier IP
- Keep the database in the Region leads to Wavelength subnet talking to the Region over the VPC
- Survive the loss of one zone leads to Several Wavelength Zones and fallback to the Region
No, when the question says
- Low latency to users in a city, not on a carrier network leads to AWS Local Zones
- Run AWS in our own data center leads to AWS Outposts
- Cache static content near users leads to Amazon CloudFront

Key takeaways

Wavelength puts EC2 and EBS inside carriers' 5G networks for the lowest latency to mobile and connected devices.
A Wavelength Zone extends a Region; opt in, then create a subnet there in your VPC.
A carrier gateway lets devices on the carrier network reach your instances through Carrier IP addresses; there is no inbound access from the internet.
Keep non-edge parts of the application in the Region, and deploy across several Wavelength Zones for resilience.
Pay On-Demand or with Savings Plans; Reserved Instances aren't available.